2017年12月四级第1套仔细阅读 Passage 1 原文翻译及答案解析

That people often experience trouble sleeping in a different bed in unfamiliar surroundings is a phenomenon known as the "first-night" effect. If a person stays in the same room the following night they tend to sleep more soundly. Yuka Sasaki and her colleagues at Brown University set out to investigate the origins of this effect.

人们在不同环境的不熟悉床上经常难以入睡，这种现象被称为“首夜效应”。如果一个人在接下来的晚上待在同一个房间，他们往往睡得更安稳。布朗大学的尤卡·佐佐木和她的同事着手研究这种效应的起源。

Dr. Sasaki knew the first-night effect probably has something to do with how humans evolved. The puzzle was what benefit would be gained from it when performance might be affected the following day. She also knew from previous work conducted on birds and dolphins that these animals put half of their brains to sleep at a time so that they can rest while remaining alert enough to avoid predators (捕食者). This led her to wonder if people might be doing the same thing. To take a closer look, her team studied 35 healthy people as they slept in the unfamiliar environment of the university's Department of Psychological Sciences. The participants each slept in the department for two nights and were carefully monitored with techniques that looked at the activity of their brains. Dr. Sasaki found, as expected, the participants slept less well on their first night than they did on their second, taking more than twice as long to fall asleep and sleeping less overall. During deep sleep, the participants' brains behaved in a similar manner seen in birds and dolphins. On the first night only, the left hemispheres (半球) of their brains did not sleep nearly as deeply as their right hemispheres did.

佐佐木博士知道首夜效应可能与人类进化的方式有关。困惑在于，当第二天的表现可能受到影响时，这种效应能带来什么好处。她还从先前对鸟类和海豚的研究中知道，这些动物一次让一半的大脑睡觉，以便它们能在休息的同时保持足够警惕以避免捕食者。这让她想知道人类是否也在做同样的事情。为了更仔细地观察，她的团队研究了35名健康人在大学心理科学系陌生环境中的睡眠情况。每位参与者在心理科学系睡了两晚，并通过监测大脑活动的技术进行了仔细监控。佐佐木博士发现，正如预期那样，参与者第一晚的睡眠质量比第二晚差，入睡时间超过两倍，总睡眠时间更少。在深度睡眠期间，参与者的大脑行为与在鸟类和海豚中观察到的相似。仅在第一晚，他们大脑的左半球睡眠深度远不及右半球。

Curious if the left hemispheres were indeed remaining awake to process information detected in the surrounding environment, Dr. Sasaki re-ran the experiment while presenting the sleeping participants with a mix of regularly timed beeps (蜂鸣声) of the same tone and irregular beeps of a different tone during the night. She worked out that, if the left hemisphere was staying alert to keep guard in a strange environment, then it would react to the irregular beeps by stirring people from sleep and would ignore the regularly timed ones. This is precisely what she found.

好奇左半球是否确实保持清醒以处理周围环境中检测到的信息，佐佐木博士重新进行了实验，在夜间向睡眠中的参与者播放同一音调的规律定时蜂鸣声和不同音调的不规则蜂鸣声混合。她推断，如果左半球在陌生环境中保持警惕，那么它会通过唤醒人们来对不规则蜂鸣声做出反应，而忽略规律定时的声音。这正是她所发现的。